CN114341074A

CN114341074A - Anti-glare surface with ultra-low glare and method of making same

Info

Publication number: CN114341074A
Application number: CN202080061985.2A
Authority: CN
Inventors: 陈海星; 陈玲; 冯江蔚; 宇辉金; 朱建强
Original assignee: Corning Inc
Current assignee: Corning Inc
Priority date: 2019-07-12
Filing date: 2020-07-06
Publication date: 2022-04-12
Also published as: TW202104127A; WO2021011215A1; US20220267195A1; EP3997042A1; KR20220034172A; JP2022540655A

Abstract

The present disclosure includes a method of making an article comprising etching a surface of a substrate with an etching suspension comprising an etching paste and glycerin such that the surface is an anti-glare surface and the article comprises no more than 1% sparkle. An article made by the method can include a substrate having a textured surface and include no more than 1% sparkle.

Description

Anti-glare surface with ultra-low glare and method of making same

Cross Reference to Related Applications

This application is entitled to priority from U.S. provisional patent application No. 62/873,554 filed 2019, 7, 12, § 119, the content of which is the basis of this application and is incorporated herein by reference in its entirety.

Background

Chemically strengthened glass is used in over five billion devices that use touch screens as a user interface. These devices include hand-held devices and automotive displays, among other consumer products. For automotive displays, optical clarity and strength at thinner aspect ratios are important for fuel economy and light weight.

Generally, these types of glass are treated for both aesthetic and functional purposes. For example, anti-reflective, anti-glare, and anti-fingerprint coatings or treatments are typically applied. In the context of automotive applications, the service life of these coatings must be longer than that on consumer electronics.

Anti-glare (AG) glass is widely used for glass displays, where external light may be reflected from the glass surface, especially in bright sunlight or in high ambient lighting conditions. When light is reflected by the glass surface, the readability of the display is improved with the anti-glare treatment applied. The AG process additionally reduces the "ghosting" effect of the reflected image, which can distract consumers interacting with the glass display.

AG processing typically uses a diffusion mechanism to diffuse reflected light on the glass surface. The principle of diffusion works to reduce the coherence of the reflected images, thereby causing unwanted images to be out of focus to the eye and reducing the interference of these images with the intended image on the display. However, the diffusion mechanism may sacrifice the sharpness and resolution of the intended image. Therefore, AG processing may affect the quality of the intended image on the glass display. AG treatments, such as chemically or mechanically texturing the glass surface, can reduce glare, but also reduce intended image resolution and cause stray glare on the glass surface, which can interfere with the intended image readability of the intended image.

Disclosure of Invention

The present disclosure provides a method of making an article comprising etching a surface of a substrate with an etching suspension comprising an etching paste and glycerol, wherein the resulting surface imparts anti-glare properties to the article. The resulting surface may be an anti-glare surface as described herein. In one or more embodiments, the anti-glare surface is an etched surface, and the article exhibits or includes no more than 1% sparkle. The glycerin achieves ultra-low sparkle on the surface of the article.

The present disclosure provides an article comprising a substrate having a textured surface and comprising no more than 1% sparkle.

The methods and articles disclosed herein can provide textured glass having ultra-low sparkle and anti-glare characteristics of less than 1%, as well as etched or anti-glare glass surfaces having a uniform appearance. For example, a consistent ultra-low flash may be maintained on the surface of the substrate.

The methods disclosed herein do not affect the mechanical properties of the glass substrate, e.g., the strength of the glass substrate can be maintained after being subjected to an anti-glare treatment to produce ultra-low sparkle.

The methods and articles disclosed herein can provide easily customized anti-glare properties of textured glass substrates by manipulating the time and chemical concentration of the etching process.

In some embodiments, the methods and articles disclosed herein can be low cost and easily scaled up.

Drawings

In the drawings, which are not necessarily drawn to scale, like numerals generally represent similar parts throughout the views. Like numerals having different letter suffixes represent different instances of substantially similar components. By way of example, and not limitation, the figures generally illustrate various embodiments discussed in this document.

Fig. 1 is a 3D topology diagram of an ultra-low sparkle textured glass substrate according to various embodiments.

Fig. 2 is a graphical representation of transmission haze and correlation of feature size for ultra-low sparkle textured glass substrates according to various embodiments.

Fig. 3 is a graphical representation of the relationship between transmission haze, sparkle, and gloss at 60 degrees for ultra low sparkle textured glass substrates according to various embodiments.

Fig. 4 is a graphical representation of the correlation of gloss, DOI, and sparkle at 60 degrees for an ultra low sparkle textured glass substrate according to various embodiments.

Detailed Description

Reference will now be made in detail to certain embodiments of the disclosed subject matter, examples of which are illustrated in the accompanying drawings. While the disclosed subject matter will be described in conjunction with the enumerated claims, it will be understood that exemplary subject matter is not intended to limit the claims to the disclosed subject matter.

Overview

Glass substrates used in displays typically require an anti-glare (AG) treatment to achieve the desired image clarity. However, AG-treated glass substrates may have higher sparkle and lower resolution of the intended image compared to untreated glass. Existing lower sparkle (2 to 3% sparkle) AG glasses, especially at image resolutions higher than 220 Pixels Per Inch (PPI), still interfere with the high resolution image on the glass display.

An ultra-low sparkle (no more than 1%) AG glass surface can provide a suitable diffusing effect to reduce reflections on internal and external illumination on the glass display but maintain image clarity. Therefore, there is a need for ultra-low sparkle AG glass surfaces having sparkle of no more than 1%.

Discussed herein are methods of making articles having anti-glare surfaces on a substrate, such as an aluminosilicate glass substrate. Articles and resulting glass articles according to one or more embodiments exhibit low sparkle and uniformity in textured surfaces and optical properties. In various embodiments, the method includes adding glycerol to the etching paste to make an etching suspension. The substrate surface is etched in a manner that has substantial uniformity to produce a low-sparkle (e.g., less than 1%) surface without impact. The process does not affect the mechanical properties of the substrate and can expand the production.

Articles produced by the methods discussed herein, for example, can have textured surfaces with feature sizes less than 5 microns and roughness ranging from about 20 nanometers to about 70 nanometers, corresponding to varying degrees of haze. These articles can additionally have a transmission haze of from about 2% to about 12%, a gloss at 60 degrees of from about 70 Gloss Units (GU) to about 130GU, and a distinctness of image (DOI) of less than 99.6. For example, the textured surface of the substrate may be covered with concave shaped features having a narrow distribution. These features give the glass substrate surface good AG and ultra low sparkle characteristics.

Substrate

Embodiments of the article use various glass substrates. For example, known forming methods (including floating glass processes and down-draw processes such as fusion draw and slot draw) may be used to form the glass substrate. In some embodiments, the glass substrate may be formed from a "phase-separable" glass composition that may undergo phase separation into two or more distinct phases after exposure to a phase separation process (such as a heating process or the like) to produce a "phase separated" glass that includes distinct glass phases having different compositions.

Glass substrates prepared by the float glass process can be characterized by a smooth surface and uniform thickness is made by floating molten glass on a base of molten metal, usually tin. In an example process, molten glass fed onto a surface of a molten tin base forms a ribbon of float glass. As the glass ribbon flows along the tin bath, the temperature is gradually reduced until the glass ribbon solidifies into a solid glass substrate that can be lifted from the tin onto the rollers. Once out of the bath, the glass substrate may be further cooled and annealed to reduce internal stresses.

The downdraw process produces glass substrates having a uniform thickness that possess relatively pristine surfaces. Since the average flexural strength of the glass substrate is controlled by the number and size of surface defects, the pristine surface with minimal contact has a higher initial strength. When this high-strength glass substrate is then further strengthened (e.g., chemically or thermally), the strength obtained is higher than that of a glass substrate having a surface that has been polished and polished. The drawn down glass substrate may be drawn to a thickness of less than about 2 millimeters. Furthermore, the drawn-down glass substrate has a very flat, smooth surface that can be used in the final application without additional grinding and polishing steps.

For example, the glass substrate may be formed using a fusion draw process that uses a draw tank having a channel for receiving molten glass feedstock. The channel has weirs that open at the top along the length of the channel on both sides of the channel. When the channel is filled with molten material, the molten glass overflows the weir. Due to gravity, the molten glass flows down to the outer surface of the draw tank in the form of two flowing glass films. These outer surfaces of the draw tank extend downwardly and inwardly so that they meet at an edge below the draw tank. The two flowing glass films are joined at this edge to fuse and form a single flowing glass substrate. The fusion draw method provides the advantage that, since the two glass films flowing through the channel are fused together, neither of the two outer surfaces of the resulting glass substrate is in contact with any part of the apparatus. Therefore, the surface characteristics of the fusion drawn glass substrate are not affected by this contact.

The slot draw process is distinguished from the fusion draw method. In the slot draw process, molten raw glass is provided to a draw tank. The bottom of the draw tank has an open slot with a nozzle extending the length of the slot. The molten glass flows through the slot/nozzle and is drawn down into the annealing zone as a continuous material.

In some embodiments, the glass components used to form the glass substrate may be dosed with about 0 mol% to about 2 mol% of at least one fining agent selected from the group consisting of: na (Na)₂SO₄、NaCl、NaF、NaBr、K₂SO₄KCl, KF, KBr, and SnO₂。

Once formed, the glass substrate may be strengthened to form a strengthened glass substrate. It should be noted that the glass-ceramics described herein may also be strengthened in the same manner as the glass substrates. As used herein, the term "strengthened material" generally refers to a glass substrate or glass-ceramic material that has been chemically strengthened (e.g., by exchanging smaller ions for larger ions in the surface of the glass or glass-ceramic material). However, other strengthening methods known in the art, such as thermal tempering, may be utilized to form the strengthened glass substrate and/or the glass-ceramic material. In some embodiments, the material may be strengthened using a combination of chemical strengthening processes and thermal strengthening processes.

The reinforced materials described herein may be chemically reinforced by ion exchange processes. In an ion exchange process, ions at or near the surface of the glass or glass-ceramic material are exchanged for larger metal ions from the bath, typically by immersing the glass or glass-ceramic material in the bath for a predetermined period of time. In one embodiment, the temperature of the molten salt bath is in the range of from about 400 ℃ to about 430 ℃ and the predetermined period of time is about four to about twenty-four hours; however, the temperature and time period of immersion may vary depending on the composition of the material and the desired strength properties. The incorporation of larger ions in the glass or glass-ceramic material strengthens the material by generating compressive stress in the region near, at or adjacent to the surface of the material (etc.). A corresponding drawing stress is induced in a central region or regions at a distance from the material surface (etc.) to balance the compressive stress. Glass or glass-ceramic materials that utilize this strengthening process can be more particularly described as chemically strengthened or ion exchanged glass or glass-ceramic materials.

In one example, potassium ions in a molten bath (such as a potassium nitrate bath) replace sodium ions in a strengthened glass or glass-ceramic material, although other alkali metal ions with larger atomic radii, such as rubidium or cesium, may also replace smaller alkali metal ions in the glass. According to particular embodiments, Ag + ions may replace smaller alkali metal ions in the glass or glass-ceramic. Similarly, other alkali metal salts, such as, but not limited to, sulfates, phosphates, halides, and the like, may be used in the ion exchange process.

At temperatures below which the glass network can relax, the process of replacing smaller ions with larger ions produces a distribution of ions across the surface of the strengthened material, thereby obtaining a stress data distribution. The larger number of incoming ions creates a Compressive Stress (CS) on the surface and a tension (central tension, CT) in the center of the strengthened material. The compressive stress is related to the central tension by the following relationship:

where t is the total thickness of the strengthened glass or glass-ceramic material and the depth of compression (DOL) of the layer is the exchange depth. The exchange depth can be described as the depth within the strengthened glass or glass-ceramic material (i.e., the distance from the surface of the glass substrate to the central region of the glass or glass-ceramic material) at which ion exchange facilitated by the ion exchange process occurs.

In one embodiment, the strengthened glass or glass-ceramic material can have a surface compressive stress of about 300MPa or greater (e.g., 400MPa or greater, 450MPa or greater, 500MPa or greater, 550MPa or greater, 600MPa or greater, 650MPa or greater, 700MPa or greater, 750MPa or greater, or 800MPa or greater). The strengthened glass or glass-ceramic material can have a depth of compression of about 15 microns or more, 20 microns or more (e.g., 25 microns, 30 microns, 35 microns, 40 microns, 45 microns, 50 microns or more), and/or a central tension of about 10MPa or more, 20MPa or more, 30MPa or more, 40MPa or more (e.g., 42MPa, 45MPa, or 50MPa, or more) but less than 100MPa (e.g., 95, 90, 85, 80, 75, 70, 65, 60, 55MPa, or less). In one or more particular embodiments, the strengthened glass or glass-ceramic material has one or more of the following (characteristics): a surface compressive stress greater than about 200MPa, a depth of the compressive layer greater than about 15 microns, and a central tension greater than about 18 MPa. In one or more embodiments, one or both of the first and second substrates have been strengthened, as described herein. In some examples, both the first substrate and the second substrate have been strengthened. Although the second substrate is strengthened by thermal energy, the first substrate may be chemically strengthened. In some examples, only one of the first and second substrates is chemically and/or thermally strengthened, while the other is not strengthened.

Any number of glass compositions may be utilized in the glass substrate and include alkali aluminosilicate glass compositions or alkali aluminoborosilicate glass compositions, although other glass compositions are also contemplated. The glass composition is characterized by being ion exchangeable. As used herein, "ion-exchangeable" means that a material comprising this component is capable of exchanging cations located at or near the surface of the material with cations of the same valence state at a larger or smaller size.

For example, suitable glass compositions include SiO₂、B₂O₃And Na₂O, wherein (SiO)₂+B₂O₃) Not less than 66 mol% and Na₂O is more than or equal to 9mol percent. In one embodiment, the glass sheet comprises at least 6 wt% (weight percent) alumina. In a further embodiment, the glass sheet comprises one or more alkaline earth oxides such that the content of alkaline earth oxides is at least 5 wt.%. Suitable glass compositions, in some embodiments, further comprise at least K₂O, MgO, and CaO. In certain embodiments, the glass can include 61 to 75 mol% SiO₂(ii) a 7 to 15 mol% of Al₂O₃(ii) a 0 to 12 mol% of B₂O₃(ii) a 9 to 21 mol% of Na₂O; 0 to 4 mol% of K₂O; 0 to 7 mol% of MgO; and 0 to 3 mol% CaO.

Further exemplary glass compositions include: 60 to 70 mol% SiO₂(ii) a 6 to 14 mol% of Al₂O₃(ii) a 0 to 15 mol% of B₂O₃(ii) a 0 to 15 mol% of Li₂O; 0 to 20 mol% of Na₂O; 0 to 10 mol% of K₂O; 0 to 8 mol% of MgO; 0 to 10 mol% CaO; 0 to 5 mol% of ZrO₂(ii) a 0 to 1 mol% of SnO₂(ii) a 0 to 1 mol% of CeO₂(ii) a Less than 50ppm of As₂O₃(ii) a And less than 50ppm of Sb₂O₃(ii) a Wherein 12mol percent is less than or equal to (Li)₂O+Na₂O+K₂O) is less than or equal to 20mol percent, and 0mol percent is less than or equal to (MgO + CaO) is less than or equal to 10mol percent.

Still further exemplary glass compositions include: 63.5 to 66.5 mol% SiO₂(ii) a 8 to 12 mol% of Al₂O₃(ii) a 0 to 3 mol% of B₂O₃(ii) a 0 to 5 mol% of Li₂O; 8 to 18 mol% of Na₂O; 0 to 5 mol% of K₂O; 1 to 7 mol% of MgO; 0 to 2.5 mol% CaO; 0 to 3 mol% of ZrO₂(ii) a 0.05 to 0.25 mol% SnO₂(ii) a 0.05 to 0.5 mol% of CeO₂(ii) a Less than 50ppm of As₂O₃(ii) a And less than 50ppm of Sb₂O₃(ii) a Wherein 14mol percent is less than or equal to (Li)₂O+Na₂O+K₂O) is less than or equal to 18mol percent, and 2mol percent is less than or equal to 7mol percent (MgO + CaO).

In another embodiment, the alkali aluminosilicate glass comprises, consists essentially of, or consists of: 61 to 75 mol% SiO₂(ii) a 7 to 15 mol% of Al₂O₃(ii) a 0 to 12 mol% of B₂O₃(ii) a 9 to 21 mol% of Na₂O; 0 to 4 mol% of K₂O; 0 to 7 mol% of MgO; and 0 to 3 mol% CaO.

In particular embodiments, the alkali aluminosilicate glass includes alumina, at least one alkali metal, and in some embodiments greater than 50 mol% SiO₂And in other embodiments at least 58 mol% SiO₂And in yet other embodiments at least 60 mol% SiO₂Wherein the proportion is as follows:

(Al₂O₃+B₂O₃) Sigma modifier>1

Wherein the proportions of the components are expressed in mol% and the modifier is an alkali metal oxide. In particular embodiments, the glass comprises, consists essentially of, or consists of: 58 to 72 mol% SiO₂(ii) a 9 to 17 mol% of Al₂O₃(ii) a2 to 12 mol% of B₂O₃(ii) a 8 to 16 mol% of Na₂O; and 0 to 4 mol% of K₂O, wherein the ratio is as follows:

(Al₂O₃+B₂O₃) Sigma modifier>1

In yet another embodiment, the alkali aluminosilicate glass substrate comprises, consists essentially of, or consists of: 60 to 70 mol% SiO₂(ii) a 6 to 14 mol% of Al₂O₃(ii) a 0 to 15 mol% of B₂O₃(ii) a 0 to 15 mol% of Li₂O; 0 to 20 mol% of Na₂O; 0 to 10 mol% of K₂O; 0 to 8 mol% of MgO; 0 to 10 mol% CaO; 0 to 5 mol% of ZrO₂(ii) a 0 to 1 mol% of SnO₂(ii) a 0 to 1 mol% of CeO₂(ii) a Less than 50ppm of As₂O₃(ii) a And less than 50ppm Sb₂O₃(ii) a Wherein Li is more than or equal to 12mol percent₂O+Na₂O+K₂O is less than or equal to 20mol percent, and MgO plus CaO is less than or equal to 10mol percent and is more than or equal to 0mol percent.

In yet another embodiment, the alkali aluminosilicate glass comprises, consists essentially of, or consists of: 64 to 68 mol% SiO₂(ii) a 12 to 16 mol% of Na₂O; 8 to 12 mol% of Al₂O₃(ii) a 0 to 3 mol% of B₂O₃(ii) a2 to 5 mol% of K₂O; 4 to 6 mol% of MgO; and 0 to 5mol percent of CaO, wherein the SiO accounts for 66mol percent or less₂+B₂O₃CaO is less than or equal to 69 mol percent; na (Na)₂O+K₂O+B₂O₃+MgO+CaO+SrO>10 mole percent; MgO, CaO and SrO are in a molar percentage ratio of not more than 5 and not more than 8; (Na)₂O+B₂O₃)≤Al₂O₃The mol percentage is less than or equal to 2; na is less than or equal to 2mol percent₂O≤Al₂O₃The mol percentage is less than or equal to 6; and 4mol percent of the total amount of the components is less than or equal to (Na)₂O+K₂O)≤Al₂O₃The mol percentage of the organic solvent is less than or equal to 10. Additional examples for generating ion-exchangeable glass structures are described in U.S. patent publication No. 2014-0087193a1 and U.S. patent No. 9,387,651, which are incorporated herein by reference in their entirety.

In an alternative embodiment, the glass substrate comprises an alkali aluminosilicate glass composition comprising: 2 mol% or more of Al₂O₃And/or ZrO₂Or 4 mol% or more of Al₂O₃And/or ZrO₂。

In some embodiments, the glass substrate comprises a glass-ceramic material that can be fusion formed or formed by other known methods, such as roll, thin roll, slot draw, or floating.

The glass-ceramics that may be used in various embodiments may be characterized by the process of forming these glass-ceramics. These glass-ceramics may be formed by a float process, a fusion process, a slot draw process, a thin roll process, or combinations thereof. Some glass-ceramics tend to have liquid viscosities, thereby precluding the use of high-throughput forming processes (such as float, slot draw, fusion draw, etc.). For example, some known glass-ceramics are formed from precursor glasses having a liquidus viscosity of about 10kP that are not suitable for fusion draw (typically requiring a liquidus viscosity of about 100kP or greater or about 200kP or greater). Glass-ceramics formed by low-throughput forming processes (e.g., thin roll type) can exhibit enhanced opacity, varying degrees of translucency, and/or surface brilliance. Glass-ceramics formed by high-throughput processes (e.g., float, slot, or fusion draw, etc.) can achieve very thin layers. The glass-ceramic formed by the fusion draw process may achieve pristine surfaces and thinness (e.g., about 2 millimeters or less). Examples of suitable glass-ceramics include Li₂O-Al₂O₃-SiO₂System (i.e., LAS system) glass-ceramic, MgO-Al₂O₃-SiO₂System (i.e., MAS-system) glass-ceramics, glass-ceramics comprising crystalline phases of one or more of mullite, spinel, alpha-quartz, beta-quartz solid solution, petalite, lithium disilicate, beta-spodumene, nepheline, and alumina, and combinations thereof.

In one or more embodiments, one or both of the first and second substrates comprises a thickness of about 3 millimeters or less. In some examples, one of the first and second substrates has a thickness of about 1 mm to about 3 mm (e.g., from about 1 mm to about 2.8 mm, from about 1 mm to about 2.6 mm, from about 1 mm to about 2.5 mm, from about 1 mm to about 2.4 mm, from about 1 mm to about 2.1 mm, from about 1 mm to about 2 mm, from about 1 mm to about 1.8 mm, from about 1 mm to about 1.6 mm, from about 1 mm to about 1.4 mm, from about 1.2 mm to about 3 mm, from about 1.4 mm to about 3 mm, from about 1.6 mm to about 3 mm, or from about 1.8 mm to about 3 mm), while the other of the first and second substrates has a thickness of less than 1 mm (e.g., about 0.9 mm or less, about 0.8 mm or less, about 0.7 mm or less, about 0.5 mm or less, about 0.55 mm or less, about 0.4 mm or less, about 3 mm or less, or less, Or about 0.2 millimeters or less). Combinations of thicknesses of the first and second substrates may include, but are not limited to, 2.1 mm/0.7 mm, 2.1 mm/0.5 mm, 1.8 mm/0.7 mm, 1.8 mm/0.5 mm, 1.6 mm/0.5 mm, 1 mm/0.7 mm, and 1 mm/0.5 mm.

The glass substrates of the disclosure typically have a dielectric constant of at least greater than 90N/mm, greater than about 95N/mm, greater than about 99N/mm; a stiffness of from about 90N/mm to about 100N/mm, about 95N/mm to about 100N/mm, or about 97N/mm to about 100N/mm, the stiffness being determined using the ball-on-ring assay at a deformation rate of 0.0017 mm/sec.

In one or more embodiments, the glass substrate may have a complex arc shape. As used herein, "complex arc," "complex arc substrate," and "complex arc substrate" refer to a non-planar shape having a complex arc, also referred to as a non-deployable shape, that includes, but is not limited to, spherical surfaces, non-spherical surfaces, and toroidal surfaces, shapes in which the curvatures of two orthogonal axes (horizontal and vertical axes) differ, e.g., can be toroidal, oblate spheroid, oblate ellipsoid, obloid, prolate ellipsoid, or shapes in which the major curvatures of the surfaces along two orthogonal planes are opposite (e.g., saddle or surface, such as saddle or monkey saddle). Other examples of complex curvatures include, but are not limited to, elliptical hyperboloids, hyperbolic parabolas, and spherical cylindrical surfaces, where the complex curvatures may have constant or varying radii of curvature. Complex arcs may also include sections or portions of these curved surfaces, or combinations of these arcs and surfaces. In one or more embodiments, the glass substrate may have compound arcs including a major radius and a cross curvature. The curvature of the glass substrate can be even more complex when a significant minimum radius is combined with a significant cross curvature and/or bending depth. Some glass substrates may also require bending along a bending axis that is not perpendicular to the longitudinal axis of the flat glass substrate.

In one or more embodiments, the glass substrate can have a radius of curvature along two orthogonal axes. In various embodiments, the glass substrate may be asymmetric. Some glass substrates prior to forming (i.e., flat surfaces or flat substrates) may also include bending along an axis that is not perpendicular to the longitudinal axis of the substrate.

In one or more embodiments, the radius of curvature may be less than 1000 millimeters, or less than 750 millimeters, or less than 500 millimeters, or less than 300 millimeters. In various embodiments, the glass substrate (including at the edges of the glass substrate) is substantially free of wrinkles or optical distortions.

In one or more embodiments, the glass substrate is characterized as a cold-formed glass substrate. In this embodiment, the glass substrate includes a first arcuate substrate and a substantially planar second substrate, wherein the second substrate is cold-formed to the curvature of the first substrate.

As used herein, cold forming includes a forming process in which a substrate and/or a glass substrate is formed at a temperature below the softening temperature of the first and second substrates to provide a complexly curved glass substrate.

Embodiments of cold-formed glass substrates may include at least one interlayer and at least one light responsive material, both of which are positioned between first and second substrates, as described herein. The cold-formed glass substrate may comprise a display unit as described herein. In one or more embodiments, the second substrate is strengthened by forming the second substrate to the curvature of the first substrate. The cold-formed glass substrate may be complexly curved as described herein.

Also contemplated herein are laminates comprising combinations of one or more glass substrates described herein. Chemically strengthened glass substrates include glass substrates treated by ion exchange strengthening processes. Chemically strengthened glass substrates typically have a thickness of about 80X 10^-7/° C to about 100 x 10^-7Coefficient of Thermal Expansion (CTE) between the/° c range. The glass substrate can be an alkali-containing form of aluminosilicate glass, borosilicate glass, aluminoborosilicate glass, or the like. One suitable commercial embodiment of the glass substrate is an aluminosilicate glass substrate. The chemically strengthened glass may have an identifiable compressive stress layer extending through at least a portion of the glass substrate. The layer of compressive stress may have a depth greater than 30 microns. The chemically strengthened glass can have a chemical strength which passes the Ring on Ring test (ROR)>Flexural strength value defined at 300 MPa. The chemically strengthened glass can have a thickness of between about 0.5 mm and about 5 mm, between about 1 and about 3 mm, less than 2 mm, from about 0.3 mm to about 4.0 mm, from about 0.5 mm to about 2 mm, or from about 0.7 mm to about 1.5 mm. The chemically strengthened glass substrate is not necessarily limited to any particular ion exchange process. For illustrative purposes, an exemplary ion-exchange strengthening process can be performed at a temperature of about 390 ℃ to about 500 ℃, or about 410 ℃ to about 450 ℃ for about 5 to about 15 hours.

Etching suspension

In accordance with one or more embodiments, the methods described herein include applying an etching suspension to a major surface of a glass substrate. An etching suspension to be applied to a glass substrate to create a textured surface includes an etching suspension formulation including glycerol having the general formula:

the etching suspension can be used to form a textured surface having ultra-low sparkle (e.g., no more than 1% sparkle).

For example, glycerol may comprise about 5 wt% to about 30 wt% of the etching suspension (e.g., about 10 wt% to about 20 wt%). For example, glycerin in the etching paste may result in ultra-low sparkle characteristics of the anti-glare surface. For example, a glycerol-containing etching paste may create a textured surface on a substrate glass having ultra-low sparkle characteristics. This is due to the glycerin in the etch paste which affects the kinetics of crystal mask nucleation and growth of AG processes (e.g., subsequent processing of the substrate to make AG features during the application of the etch paste), which results in a uniform and small surface feature distribution. In particular, glycerol may limit the growth of the glass mask on the crystal surface, while achieving smaller feature sizes, compared to an etching suspension without such a solvent. Additionally, glycerol may increase the viscosity of the solution, resulting in a slower, uniform distribution of the etching suspension across the substrate surface, which may result in good uniformity of the textured AG surface. The unique surface feature distribution can achieve uniformity of ultra-low sparkle and anti-glare properties across the surface of the substrate.

The etching suspension optionally further comprises Propylene Glycol (PG). For example, the etching suspension can comprise from about 1 wt% to about 15 wt% (e.g., about 2 wt% to about 10 wt%). In some instances, the addition of PG can affect the uniformity of the etching suspension, thus requiring further mixing prior to etching.

For example, the etching suspension may contain about 10 wt% to about 20 wt% NH₄F and about 0 wt% to about 5 wt% NH₄HF₂About 5 wt% to about 20 wt% KF, about 5 wt% to about 15 wt% FeCl₃KNO in an amount of about 5 wt% to about 10 wt%₃And about 5 wt% to about 10 wt% BaSO₄(filler material). The etching suspension may alternatively contain other soluble metal salts, such as CuCl₂、Fe₂(SO₄)₃、Fe(NO₃)₃、CoCl₂、Co₂SO₄、Co(NO₃)₂、NiCl₂、Ni₂SO₄、Ni(NO₃)₂、ZnCl₂、Zn₂SO₄、Zn(NO₃)₂、CaCl₂、Ca₂SO₄、Ca(NO₃)₂、MgCl₂、Mg₂SO₄、Mg(NO₃)₂For example, it may also be combined with glycerin to produce a similar ultra-low sparkle surface. Optionally, the etching suspension may contain a chelating agent.

For example, the etching suspension may be an aqueous solution and may be prepared by mixing an appropriate soluble metal salt in water and adding glycerol and an acid component (e.g., an appropriate acid, HF, HCl, or other acid in the etching art). Other components may be added as appropriate. The etching suspension may be further mixed before etching to uniformly apply the etching suspension to the glass substrate in the etching step.

Etching process

According to one or more embodiments of this method, an etching suspension is used to process a glass substrate and make a glass substrate that exhibits ultra-low sparkle (i.e., no more than 1% sparkle). For example, the etching process may be a subtractive chemical process in which the substrate glass is contacted with the etching suspension at varying contact times to produce textured features on the surface of the glass substrate. The etching process may create the textured features by selectively removing material from the substrate surface to create the textured features.

First, the substrate may optionally be cleaned, such as, for example, with a cleaning agent or other suitable solvent. For example, after cleaning, the substrate may be rinsed with Deionized (DI) water or other solvents (e.g., ethanol). The cleaning step may enable a process to remove impurities or other contaminants from the surface of the glass substrate to be etched.

Next, a portion of the substrate may be laminated with a mask material to protect portions or surfaces of the substrate glass that will not be etched. For example, one side of the glass substrate may be laminated with a masking material to enable (the process of) etching only the other side of the glass substrate to make AG features on only one side of the substrate. For example, lamination may be performed with an acid resistant film, such as polyethylene or other suitable organic film that will prevent the etching process of the acid and etching suspension on this surface.

The glass substrate can then be contacted with a dilute acid solution (such as, for example, HCl, HF, combinations thereof, or other suitable dilute acid solutions). The contacting process may be performed by immersion, wiping, or other suitable methods. For example, the first contacting step can be performed for about 5 seconds to about 10 seconds. Alternatively, the glass substrate may be cleaned, such as, for example, by rinsing with DI or other suitable solvent, or by wiping before and/or after the first contact. This initial acid contact removes contaminants from the glass surface and activates the surface to achieve a more uniform treatment.

Subsequently, the substrate may be etched with the etching suspension (as described above) to achieve the first etching. As with the first acid bath, the substrate may be contacted with the etching suspension (e.g., by immersion, wiping, or other suitable method). For example, the contact with the etching suspension may be from about 15 seconds to about 3 minutes (e.g., about 30 seconds to about 120 seconds). After the first etching step, the glass substrate may optionally be cleaned, such as by rinsing or wiping with DI or other suitable solvent.

Since the etching suspension contains glycerol, the etching suspension can, for example, be distributed uniformly over the substrate glass after the first etching contact. Depending on the viscosity of the solution, the addition of glycerol to the solution allows the kinetics of etching to proceed rapidly. The etching suspension can be diffused very rapidly to the surface of the substrate glass. While not wishing to be bound by any particular theory, it is believed that this result is due, at least in part, to the relatively high surface tension of glycerol at 64.00mN/m (20 ℃). The high surface tension allows the etching suspension to move rapidly along the substrate once exposed. Additionally, the viscosity of the etching suspension containing glycerol may be from about 20cPs to about 500cPs, or about 215cPs higher than conventional etching suspensions used for AG glass substrate processing. This prevents excessive movement of the etching suspension and dropping off the substrate. The fast moving nature of the glycerol-containing etching suspension enables rapid, relatively uniform etching of glass substrates.

An optional second etch may be performed by contacting the glass substrate with the etching suspension a second time. For the second etch, the substrate may be cleaned (i.e., wiped or rinsed) as described above prior to contacting. The substrate may be contacted with the etching suspension, for example, by immersion, wiping, or other suitable methods known in the art. For example, the second etch may last from about 60 seconds to about 180 seconds. In some embodiments, the second etching may enable a polishing process of the glass substrate AG features. After the second etch, the glass substrate can optionally be cleaned, such as by rinsing with DI or other suitable solvent, or by wiping. After the etching step, the glass substrate can optionally be chemically strengthened (such as by ion exchange) as discussed above.

Textured surfaces

The resulting articles, produced by the various embodiments of the methods described herein, exhibit an etched surface. The etched surface may be described as textured. Embodiments of articles having such surfaces exhibit or include, no more than 1% ultra-low sparkle. The glycerol in the etching suspension creates a surface that results in low sparkle performance, in part due to the nature of the solution that moves across the substrate during the etching process (as described above). In some embodiments, the sparkle is no more than 0.7% (e.g., no more than 0.6%). The surface area of the etched, textured surface can have, for example, a surface area from about 1.5 to about 50 times greater than the surface area of the starting, unetched substrate.

In various embodiments, the article may have a textured surface with a surface roughness of less than about 5 microns. In some embodiments, the textured surface can have a surface roughness of from about 20 nanometers to about 70 nanometers (e.g., about 30 nanometers to about 60 nanometers).

In various embodiments, the textured surface can have, for example, a very large number of concave features due to etching, to achieve a discrete effect that results in an anti-glare surface. Alternatively, the features may be, for example, concave, convex, honeycomb, bowl, or other patterned features. These features may, for example, be narrowly distributed along the surface of the AG glass to achieve more effective anti-glare properties. The features may substantially cover the entire surface. The concave features may be narrowly distributed, i.e., having an average size with a percentage of features greater than 30% of the total number of features. Here, about 41% of the features may be in a range from about 3.5 microns to about 5.5 microns (e.g., a size from about 4.4 microns to about 4.8 microns, or about 4.5 microns to about 4.7 microns).

In various embodiments, the textured surface can have a transmission haze of from about 2% to about 12%. (e.g., from about 3% to about 11%). Additionally, the textured surface may have a gloss measured at a 60 degree angle (at a 60 degree gloss), where the 60 degree gloss is about 70 Gloss Units (GU) to about 130GU (e.g., about 80GU to about 120 GU). In general, transmission haze and gloss are inversely proportional. The amount of time spent in each etching step reduces the gloss and increases the haze (i.e., less time polishing) without increasing the gloss and reducing the haze (i.e., more time polishing). This inverse relationship allows for tuning of the etch time and tailoring of the etch process to the end use of the AG glass substrate.

In various embodiments, the textured surface may have a DOI (image clarity) of less than 99.6, or preferably less than 99.4, and a gloss of less than 120.

The textured surface can have, for example, a lateral dimension of about 200 microns (e.g., about 100 microns). Lateral dimensions are a measure of the feature size according to a roughness scale (as opposed to a feature size that can be determined by a microscope). The textured surface can have a depth of about 30 microns (e.g., about 2 microns), which is defined by the arithmetic mean deviation of the roughness data distribution. The continuous density of features on the textured surface (i.e., the density across the entire surface of the substrate) may be, for example, about 10% to about 100%.

Definition of

Throughout this document, values expressed in a range format should be interpreted in a flexible manner to include not only the numerical values explicitly recited as the limits of the range, but also to include all the individual numerical values or sub-ranges encompassed within that range as if such individual numerical values and sub-ranges are explicitly recited. For example, a range of "about 0.1% to about 5%" or "about 0.1% to 5%" should be interpreted to include not only about 0.1% to about 5%, but also include the individual values (e.g., 1%, 2%, 3%, and 4%) and the sub-ranges within the specified range (e.g., 0.1% to 0.5%, 1.1% to 2.2%, 3.3% to 4.4%). Unless otherwise specified, the term "about X to about Y" has the same meaning as "about X to about Y". Likewise, unless otherwise specified, the term "about X, Y, or about Z" has the same meaning as "about X, about Y, or about Z".

In this document, the terms "a", "an", or "the" are used to include one or more than one unless the context clearly dictates otherwise. The term "or" is used to mean a non-exclusive "or" unless otherwise stated. The term "at least one of A and B" has the same meaning as "A, B, or A and B". Also, it is to be understood that the phraseology or terminology employed herein, and not otherwise defined, is for the purpose of description only and not of limitation. Any use of paragraph headings is intended to aid in reading the document and should not be construed as limiting; information related to a paragraph title may occur within or outside of this paragraph.

In the methods described herein, acts may be performed in any order, unless time or order of operation is explicitly recited, without departing from the principles of the disclosure. Further, unless explicitly recited in a claim language, given actions may be performed concurrently. For example, the claimed X behavior and the claimed Y behavior may be carried out concurrently within a single operation, and the resulting process would fall within the literal scope of the claimed process.

The term "about" as used herein can allow for a variable degree of value or range, e.g., within 10%, within 5%, within 1% of the value or limits of the range recited, and includes the exact recited value or range.

The term "substantially" as used herein means a majority, such as at least about 50%, 60%, 70%, 80%, 90%, 95%, 96%, 97%, 98%, 99%, 99.5%, 99.9%, 99.99%, or at least about 99.999%, or more, or 100%.

As used herein, the term "light" refers to electromagnetic radiation within and near the wavelengths visible to the human eye and includes Ultraviolet (UV) and infrared light at wavelengths from about 10 nanometers to about 300000 nanometers.

The term "solvent" as used herein refers to a liquid that can dissolve a solid, liquid, or gas. Non-limiting examples of solvents are silicones, organic complexes, water, alcohols, ionic liquids, and supercritical fluids.

The term "room temperature" as used herein refers to a temperature of about 15 ℃ to 28 ℃.

The term "surface" as used herein refers to a boundary or side of an object, wherein such boundary or side may have any perimeter shape and may have any three-dimensional shape, including planar, arcuate, or angular, wherein the boundary or side may be continuous or discontinuous. The term surface generally refers to the outermost layer of the object, without the implied boundary of depth, but when the term "holes" is used to refer to a representative surface, this term refers to both surface openings and the depth to which the holes extend into the substrate below the surface.

As used herein, "anti-glare" refers to the physical transformation of light into contact with a treated surface of an article (such as a display) that alters the disclosure, or the property of light reflected from the surface of the article to be diffusely reflected rather than specularly reflected. In embodiments, the surface treatment may be produced by mechanical or chemical etching. The anti-glare does not reduce the amount of light reflected from the surface, but only changes the characteristics of the reflected light. The image reflected by the antiglare surface does not have sharp boundaries. In contrast to anti-glare surfaces, anti-reflective surfaces are typically thin film coatings that reduce light reflection from the surface via the use of refractive index changes and, in some examples, destructive interference techniques.

As used herein, "contacting" refers to an intimate physical touch that can acquire a physical change, a chemical change, or both a physical and chemical change. In the present disclosure, various particle deposition or contacting techniques, such as spraying, dipping, and the like, may provide a surface that is granular when contacted as illustrated and shown herein. Additionally or alternatively, as illustrated and demonstrated herein, various chemical treatments of the particulated surface, such as spraying, immersion, and similar techniques, or combinations thereof, may provide an etched surface upon contact with one or more etchant complexes.

As used herein, "transmission haze" or "haze" refers to a particular surface light scattering property that is related to surface roughness. Haze measurements may be performed, for example, with instruments such as the BYK Haze-Gard and ASTM D1003 methods. The haze measurement method is explicitly described in more detail below.

As used herein, "roughness" or "surface roughness (Ra)" is on or below the microscopic level, uneven or irregular surface condition. Roughness metrology may be used to determine the lateral dimensions of features, as discussed below.

"image clarity" or "DOI" as used herein refers to the sharpness of an image as measured by the Rhopoint IQ-S20 °/60 °/85 ° instrument, standard ASTM D5767 method. A glass reflectance quantitative method was performed on at least one roughened surface of a glass sheet at a specular viewing angle and at an angle slightly deviating from the specular viewing angle according to method A of ASTM 5767. The values obtained from these measurements are combined to provide a DOI value.

As used herein, "gloss" or "gloss level" refers to surface luminance, brightness, or sparkle, and more specifically, to a measure of specular reflectance calibrated to a standard according to ASTM process D523 (such as, for example, the certified black glass standard), the entire contents of ASTM process D523 being incorporated herein by reference. Common gloss measurements are typically made at incident light angles of 20 °, 60 °, and 85 °, while the most common gloss measurements are made at 60 °. However, due to the wide acceptance angle of this measurement, ordinary gloss often cannot distinguish between surfaces with high and low distinctness-of-reflected-image (DOI) values. An anti-glare surface of a glass article having a gloss (i.e., the amount of light reflected from a sample at a particular angle relative to a standard) of up to 90SGU (standard gloss units), as measured according to ASTM standard D523, and in one embodiment, has a gloss in a range of about 60SGU up to about 80 SGU. See also DOI definitions above.

As used herein, "feature size," "ALF," or "average characteristic maximum feature size" refers to the measured value of surface feature variation in the x and y directions (i.e., in the plane of the substrate, as discussed further herein.

As used herein, "lateral dimension" or "lateral feature dimension" refers to a measure of lateral surface feature variation in the x and y directions, i.e., in the plane of the substrate, as discussed further herein. For example, the lateral dimensions may be determined by the roughness metrology described herein.

As used herein, "continuous density" refers to the density of features of the overall substrate in the entire x and y directions, i.e., in the plane of the substrate.

As used herein, "individual density" refers to the density of features for a particular portion of a substrate in the entire x and y directions, i.e., in the plane of the substrate.

As used herein, "sparkle" refers to the relationship between the size of a feature on at least one rough glass surface and the pixel pitch of interest (particularly the minimum pixel pitch). Display "sparkle" is typically assessed by human visual inspection of materials placed adjacent to the pixelated display. ALF and ALF have been found to have a relationship to display "sparkle" that is an effective basis for metrology for different materials having different surface morphologies, including glasses of different compositions and particle coated polymeric materials. There is a strong correlation between the average maximum characteristic feature size (ALF) and the visual rating showing sparkle severity across a number of different sample materials and surface morphologies. In an embodiment, the glass article may be a glass panel forming a portion of a display system. The display system may include a pixilated image display panel disposed adjacent to the glass panel. The minimum pixel pitch of the display panel may be greater than ALF.

"uniformity" or "uniformity" as used herein refers to the surface quality of an etched sample. Surface uniformity is typically assessed by human visual inspection at various angles. For example, the glass article sample is held at approximately eye height and then slowly rotated from 0 to 90 degrees under standard white fluorescent lamp conditions. If the viewer does not detect pinholes, cracks, ripples, cracks, or other similar defects, the surface quality is considered "uniform"; otherwise the sample is considered to be non-uniform. A "good" or "OK" rating indicates that the uniformity is acceptable or satisfactory, the former being subjectively superior to the latter.

Examples of the invention

Various embodiments of the disclosure may be better understood with reference to the examples provided by way of illustration. The present disclosure is not limited to the examples given herein.

Ten anti-glare glass articles (examples 1 to 10) having a rough surface were produced by an etching process in which the etching suspension contained glycerin. The substrate used was an aluminosilicate glass substrate from Corning (Corning) that had not been chemically strengthened (e.g., ion exchanged).

In addition to the acid component and other fillers, this etching suspension contains both etching paste (shanghai aladine biochemical technologies, ltd.) and glycerol (shanghai aladine biochemical technologies, ltd.). The total etching suspension contains 10 to 20 wt% of NH₄F and 0 to 5 wt% NH₄HF₂5 to 20 wt% of KF, 5 to 15 wt% of FeCl ₃5 to 10 wt% of KNO ₃5 to 10 wt% BaSO as filler₄And 5 to 30 wt% of glycerol.

The etching suspension is prepared by weighing and mixing solid powder chemicals (e.g., etching paste salts). Deionized (DI) water is added from 10 wt% to 40 wt% and the solution is stirred. Subsequently, from about 5 wt% to about 20 wt% hydrofluoric acid (40%) solution was added and slowly mixed from about 5 wt% to about 10 wt% glycerol with manual stirring. Once all the chemicals were in solution, manual stirring was continued until a suspension was formed. The etching suspension is further stirred with a mechanical stirrer for about 2 hours or left to stand at ambient conditions for up to 24 hours until chemical equilibrium is reached. The preparation of the etching suspension was performed at room temperature.

Prior to the etching process, the glass substrate is cleaned with a cleaning agent to remove contaminants, and then cleaned with an ultrasonic bath of deionized water. After the cleaning process, the glass substrate is laminated with a polyethylene film (i.e., an acid-resistant film) to protect the non-etched surface of the substrate glass. After the lamination operation, the substrate glass was immersed in the diluted HF and HCl mixed solution for about 5 to 10 seconds. Subsequently, the glass was lifted from the acid solution and rinsed in a deionized water bath for about 10 seconds.

The glass substrate was then immersed in the etching suspension in the tank for 30 seconds to 120 seconds, as shown in table 1 below. The glass substrate was then lifted out of the etching suspension and rinsed in a deionized water bath for about 10 seconds. The glass substrate is polished in a HF and HCl solution for about 60 seconds to about 180 seconds. The glass substrate was then rinsed and cleaned with DI. After this, the glass substrate was delaminated and air-dried. The specific etching and polishing times for each of examples 1 to 10 are shown in table 1 below.

Table 1: etching conditions of examples 1 to 10.

The optical properties of examples 1 to 10 were measured with a Rhopoint gloss meter (Rhopoint Instruments ltd., st. leonards, uk) and a BYK haze meter (BYK Additives & Instruments, Wesel, germany). Sparkle was measured using an SMS-1000 bench top model (Display-Messtechnik & Syseme, Calseme, Germany) at 140 Pixels Per Inch (PPI). The roughness of the textured surface was measured by a Mitutoyo SJ-310 roughness meter (Mitutoyo u.s.a., Aurora, IL). Table 2 below summarizes the optical and surface properties of examples 1-10.

Gloss and DOI at 60 degrees were measured with Rhopoint gloss meter using standard measurement methods. Gloss is measured as being proportional to the amount of light reflected from the surface. The measurement geometry is selected based on the reflectance of the material at a gloss level of 60 degrees, medium in Gloss Units (GU). The DOI is measured based on the degree of sharpness of the reflected image appearing in the reflective surface. Signs of poor DOI include orange peel, brush marks, waviness, or other structures visible on the surface, or locations where the reflected image is distorted. Possibly resulting in poor DOI associated with surface features. The DOI is measured on a DOI measurement scale of 0 to 100, where 100 is a smooth surface.

Haze, transmission, and transmission Haze were measured using a BYK Haze-Guard and ASTM D1003 Haze Meter (Process A) standard method. When viewing an object through a material, light that is scattered while passing through a film or sheet of material can create a field of fog or smoke. This method uses light scattering of the sample to quantify transmission haze, transmittance, and transmission haze.

Specifically, in ASTM D1003 process a, a collimated beam from a light source is passed through a sample mounted on the inlet port of an integrating sphere in the instrument. Light is measured by a photodetector positioned at 90 ° to the entrance port and is uniformly distributed through the matt white highly reflective coating on the spherical wall. A baffle mounted between the photodetector and the inlet port prevents exposure from the straight port. An exit port directly opposite the entrance port contains a light trap for absorbing all light from the light source in the absence of the sample. A shutter, coated with the same coating as the wall of the sphere, is applied in this outlet port, allowing the port to be opened and closed as desired. The total transmission is measured with the exit port closed. Transmission haze was measured with the outlet port open.

The flash was measured using an SMS-1000 bench instrument. With this instrument, the sparkle was measured by applying a scattering antiglare layer (glass or polymer film) to a display screen with a specific pixel array pitch and the image of this combination was taken with the camera of SMS 1000. The recorded image is digitally low-pass filtered to account for the limited angular resolution of the human eye and to separate the display pixel modulation from the flash. When the antiglare layer is not fixed to the display pixel array, a difference image is created by first exposing from two cameras with the antiglare layer slightly translated before applying spatial filtering. The degree of sparkle was evaluated by dividing the standard deviation of the gray scale distribution of the filtered image by the mean.

Table 2: the anti-glare properties of the ultra-low sparkle textured examples 1 to 12 produced by the etching paste added with the organic solvent glycerin.

Examples 1 to 10 show ultra-low flash values of < 1% while maintaining a suitable anti-glare effect (e.g., transmission haze of about 2% to about 12%). The optical properties of examples 1 to 10 also show that a wide range of optical properties are achieved when an etching suspension comprising glycerol is applied to a glass substrate with different etching and polishing times. For example, the antiglare effect of the substrate can be tailored depending on the specific antiglare requirements while maintaining a low sparkle of less than 1% by adjusting the polishing time of the glass substrate, as shown in table 2.

The surface morphology of examples 1 to 10 was tested with Nikon Eclipse L200N (Nikon Metrology, Brighton, MI). Generally, the adjustment of the polishing time from 60 seconds to 120 seconds affects the surface morphology of examples 1 to 10. Adjusting the polishing time affects the transmission haze of the examples. For example, as the polishing time was gradually increased from 60 seconds to 170 seconds, the transmission haze changed from 11.1% to 2.09%. This also affects the characteristic dimensions of the surfaces of examples 1-10 (as determined by the longest dimension along the x-y plane), which vary from about 4 microns to about 5 microns. Feature sizes are determined by spectroscopy (as opposed to lateral sizes that can be determined by asperity metrology).

Fig. 1 illustrates a topology of the textured surface of example 6 fabricated on an aluminosilicate glass substrate. The topology was mapped by a Keyence confocal laser scanning microscope (Keyence America, Itasca, IL). The glass surface has many small protrusions thereon, which can, for example, improve the tactile feel as compared to bare glass. The average roughness of the textured glass surface of the glass is shown in table 3 below. An arithmetic mean deviation (Ra) of the roughness data distribution, a maximum height (Rz) of the roughness data distribution, a mean width (RSm) of the roughness data distribution element, a maximum data distribution peak height (Rp) of the roughness data distribution, a maximum data distribution valley depth (Rv) of the roughness data distribution, a mean height (Rc) of the roughness data distribution element, a total height (Rt) of the roughness data distribution, a root mean square deviation (Rq) of the roughness data distribution, a skewness (Rsk) of the roughness data distribution, and a kurtosis (Rku) of the roughness data distribution are shown.

Table 3: roughness metrology shown in microns in example 6.

Ra (arithmetic mean deviation of roughness data distribution) is about 0.04 microns and can vary from 0.02 microns to 0.07 microns at various degrees of haze. Additionally, Rsk and Rku, which describe the sharpness of the textured surface, are 1 to 3 and 3 to 8, respectively. For example, in this example, Rsk and Rku (respectively) are 1.4 and 4.2.

Examples 1-10 generally show the appearance of a substantially uniform anti-glare (AG) coating. For example, example 6 is a textured surface on an aluminosilicate glass having a composition including about 64 mol% (mole percent) SiO2, 16 mol% Al2O3, 11 mol% Na2O, 6 mol% Li2O, 1 mol% ZnO, and 2.5 mol% P2O 5. Template 6 sample size was 2 "x 2". As shown in table 2, example 6 had a transmission haze of 5.5%, a gloss at 60 degrees of 116.7, a clarity of image (DOI) of 99.4, a sparkle of 0.65, with a feature size of 4.7 microns. Example 6 was slightly diffuse to ambient light via visual inspection and the image was always kept sharp when viewed through transmission of the sample. Therefore, an ultra-low sparkle textured glass, such as example 6, should have an AG effect while displaying a clear image.

Fig. 2 illustrates a graphical representation of transmission haze and feature size dependence for examples 1-10, according to various embodiments. Here, as the feature size increases, the transmission haze gradually decreases. This may be due to increased polishing time for feature sizes.

Fig. 3 illustrates a graphical representation of the relationship between transmission haze, 60 degree viewing angle gloss for examples 1-10, according to various embodiments. There is a positive correlation between transmitted haze and sparkle (in the range of less than 1%), and an inverse relationship is observed between gloss and haze as expected.

Fig. 4 illustrates a graphical representation of 60 degree view angle gloss, DOI, correlation of sparkle for examples 1-10, in accordance with various embodiments. Fig. 4 illustrates the correlation of 60 degree viewing angle gloss, DOI, sparkle for examples 1-10. According to the measured results examples 1 to 10 (see table 2), the DOI is between 99.3 and 99.4 when the gloss at 60 degrees is less than 120. Generally, lower gloss results in a stronger antiglare effect, while sparkle increases and DOI decreases. For this reason, at ultra-low sparkle < 1%, it is preferable to keep the gloss and DOI low at 60 degrees. In examples 1 to 10, the DOI is less than about 99.4 when the gloss at 60 degrees is from about 80GU to about 120 GU.

The terms and expressions which have been employed are used as terms of description and not of limitation, and there is no intention in the use of such terms and expressions of excluding any equivalents of the features shown and described or portions thereof, but it is recognized that various modifications are possible within the scope of the embodiments of the disclosure. Thus, it should be understood that although the present disclosure and optional features have been specifically disclosed by specific embodiments and optional features, modification and variation of the concepts herein disclosed may be resorted to by those skilled in the art, and that such modifications and variations are considered to be within the scope of the embodiments of this disclosure.

Additional embodiments

The following exemplary embodiments are provided, and the numbering of these embodiments should not be construed to designate importance:

embodiment 1 includes a method of making an article comprising etching a surface of a substrate with an etching suspension comprising an etching paste and glycerol, wherein the article comprises no more than 1% sparkle.

Embodiment 2 includes embodiment 1, wherein the etching suspension comprises from about 5 wt% to about 30 wt% glycerol.

Embodiment 3 includes any one of embodiments 1-2, wherein the etching paste includes one or more salts selected from the group consisting of: NH (NH)₄F、NH₄HF₂、KF、FeCl₃、KNO₃、BaSO₄、CuCl₂、Fe₂(SO₄)₃、Fe(NO₃)₃、CoCl₂、Co₂SO₄、Co(NO₃)₂、NiCl₂、Ni₂SO₄、Ni(NO₃)₂、ZnCl₂、Zn₂SO₄、Zn(NO₃)₂、CaCl₂、Ca₂SO₄、Ca(NO₃)₂、MgCl₂、Mg₂SO₄、Mg(NO₃)₂And combinations thereof.

Embodiment 4 includes any of embodiments 1-3, wherein the etch paste includes from about 10 wt% to about 20 wt% NH₄F。

Embodiment 5 includes any one of embodiments 1 through 4, wherein the etch paste includes from about 0 wt% to about 5 wt% NH₄HF₂。

Embodiment 6 includes any one of embodiments 1-5, wherein the etch paste includes from about 5 wt% to about 20 wt% glycerin.

Embodiment 7 includes any of embodiments 1 through 6, wherein the etch paste includes from about 5 wt% to about 15 wt% FeCl₃。

Embodiment 8 includes any one of embodiments 1 through 7, wherein the etch paste comprises from about 5 wt% to about 10 wt% KNO₃。

Embodiment 9 includes any one of embodiments 1 to 8, wherein the etch paste includes from about 5 wt% to about 10 wt% BaSO₄。

Embodiment 10 includes any one of embodiments 1-9, further comprising preparing an etching paste by mixing the one or more salts with glycerol.

Embodiment 11 includes any one of embodiments 1 to 10, further comprising cleaning the substrate prior to etching.

Embodiment 12 includes any one of embodiments 1-11, further comprising laminating the substrate prior to etching.

Embodiment 13 includes any one of embodiments 1 to 12, further comprising delaminating the substrate after etching.

Embodiment 14 includes any one of embodiments 1 to 13, wherein etching includes at least two etching steps.

Embodiment 15 includes any one of embodiments 1 to 14, wherein etching comprises: contacting the substrate with a dilute acid solution and optionally rinsing the substrate; contacting the substrate with an etching suspension to effect a first etch and optionally rinsing the substrate; and optionally contacting the substrate with an etching suspension to effect a second etch, and optionally rinsing the substrate.

Embodiment 16 includes any one of embodiments 1 to 15, wherein contacting the substrate with the etching suspension is performed for about 5 seconds to about 10 seconds.

Embodiment 17 includes any one of embodiments 1 to 16, wherein contacting the substrate with the etching suspension is performed for about 30 seconds to about 120 seconds.

Embodiment 18 includes any one of embodiments 1 to 17, wherein contacting the substrate with the etching suspension is performed for about 60 seconds to about 180 seconds.

Embodiment 19 includes any one of embodiments 1 to 18, further comprising cleaning the substrate after etching.

Embodiment 20 includes any one of embodiments 1-19, further including a step of chemically strengthening the substrate.

Embodiment 21 includes any one of embodiments 1-20, wherein the chemically strengthened substrate comprises an ion exchange substrate.

Embodiment 22 includes an article comprising a substrate having a textured surface and comprising no more than 1% sparkle.

Example 23 includes example 22, wherein the sparkle is no more than 0.7%.

Embodiment 24 includes any one of embodiments 22-23, wherein the sparkle is no more than 0.6%.

Embodiment 25 includes any one of embodiments 22-24, wherein the substrate is chemically strengthened glass.

Embodiment 26 includes any one of embodiments 22-25, wherein the textured surface has a surface roughness of less than 5 microns.

Embodiment 27 includes any one of embodiments 22-26, wherein the textured surface has a surface roughness from about 20 nanometers to about 70 nanometers.

Embodiment 28 includes any one of embodiments 22 to 27, wherein the textured surface has a surface roughness from about 30 nanometers to about 60 nanometers.

Embodiment 29 includes any one of embodiments 22-28, wherein the textured surface comprises concave, convex, honeycomb, bowl-shaped, or patterned features.

Embodiment 30 includes any of embodiments 22-29, wherein the concave features are narrowly distributed and completely cover the textured surface.

Embodiment 31 includes any one of embodiments 22-30, wherein the concave features comprise a dimension from about 4 microns to about 5 microns.

Embodiment 32 includes any one of embodiments 22-31, wherein the concave features comprise a dimension from about 4.4 microns to about 4.8 microns.

Embodiment 33 includes any one of embodiments 22 to 32, wherein the textured surface has a transmission haze from about 2% to about 12%.

Embodiment 34 includes any of embodiments 22 to 33, wherein the textured surface has a gloss at 60 degrees from about 70GU to about 130 GU.

Embodiment 35 includes any of embodiments 22 to 34, wherein the textured surface has a gloss at 60 degrees from about 80GU to about 120 GU.

Embodiment 36 includes any one of embodiments 22 to 35, wherein the textured surface has a distinctness of image (DOI) of less than about 99.6.

Embodiment 37 includes any one of embodiments 22 to 36, wherein the textured surface has a distinctness of image (DOI) of less than about 99.4.

Embodiment 38 includes any one of embodiments 22-37, wherein the textured surface has a lateral dimension of about 200 microns.

Embodiment 39 includes any one of embodiments 22-38, wherein the textured surface has a lateral dimension of about 100 microns.

Embodiment 40 includes any one of embodiments 22-39, wherein the textured surface has a depth of about 30 microns defined by an arithmetic mean deviation of the roughness data distribution.

Embodiment 41 includes any one of embodiments 22-40, wherein the textured surface has a depth of about 2 microns defined by an arithmetic mean deviation of the roughness data distribution.

Embodiment 42 includes any one of embodiments 22 to 41, wherein the continuous density of features on the textured surface is about 10% to about 100%.

Claims

1. A method of making an article comprising:

etching a surface of a substrate with an etching suspension comprising an etching paste and glycerol, wherein the article comprises no more than 1% sparkle.

2. The method of claim 1, wherein the etching suspension comprises from about 5 wt% to about 30 wt% glycerol.

3. The method of any one of the preceding claims, wherein the etching paste comprises one or more salts selected from the group consisting of: NH (NH)₄F、NH₄HF₂、KF、FeCl₃、KNO₃、BaSO₄、CuCl₂、Fe₂(SO₄)₃、Fe(NO₃)₃、CoCl₂、Co₂SO₄、Co(NO₃)₂、NiCl₂、Ni₂SO₄、Ni(NO₃)₂、ZnCl₂、Zn₂SO₄、Zn(NO₃)₂、CaCl₂、Ca₂SO₄、Ca(NO₃)₂、MgCl₂、Mg₂SO₄、Mg(NO₃)₂And combinations thereof.

4. The method of claim 3, wherein the etch paste comprises from about 10 wt% to about 20 wt% NH₄F。

5. The method of claim 3 or claim 4, wherein the etch paste comprises from about 0 wt% to about 5 wt% NH₄HF₂。

6. The method of any one of claims 3-5, wherein the etch paste comprises from about 5 wt% to about 20 wt% KF.

7. The method of any of claims 3-6, wherein the etch paste comprises from about 5 wt% to about 15 wt% FeCl₃。

8. The method of any of claims 3-7, wherein the etch paste comprises from about 5 wt% to about 10 wt% KNO₃。

9. The method of any of claims 3-8, wherein the etch paste comprises from about 5 wt% to about 10 wt% BaSO₄。

10. The method of any of claims 3-9, further comprising: the etching paste is prepared by mixing the one or more salts with the glycerin.

11. The method of any of the preceding claims, further comprising: the substrate is cleaned prior to etching.

12. The method of any of the preceding claims, further comprising: the substrate is laminated prior to etching.

13. The method of any of the preceding claims, further comprising: delaminating the substrate after etching.

14. The method of any one of the preceding claims, wherein etching comprises at least two etching steps.

15. The method of any of the preceding claims, wherein etching comprises:

contacting the substrate with a dilute acid solution and optionally rinsing the substrate;

contacting the substrate with the etching suspension to effect a first etch and optionally rinsing the substrate; and

optionally contacting the substrate with the etching suspension to effect a second etch, and optionally rinsing the substrate.

16. The method of claim 15, wherein contacting the substrate with the dilute acid solution is performed for about 5 seconds to about 10 seconds.

17. The method of claim 15, wherein contacting the substrate with the etching suspension is performed for about 30 seconds to about 120 seconds.

18. The method of claim 15, wherein contacting the substrate with the etching suspension is performed for about 60 seconds to about 180 seconds.

19. The method of any of the preceding claims, further comprising: the substrate is cleaned after etching.

20. The method of any of the preceding claims, further comprising: and strengthening the substrate.

21. The method of claim 20, wherein strengthening the substrate comprises: chemically strengthening the substrate.

22. An article of manufacture, comprising:

a substrate having a textured surface and comprising no more than 1% sparkle.

23. The article of claim 22, wherein the sparkle is no more than 0.7%.

24. The article of claim 22 or claim 23, wherein the sparkle is no more than 0.6%.

25. The article of any one of claims 22-24, wherein the substrate is strengthened glass.

26. The article of any one of claims 22-25, wherein the textured surface has a surface roughness of less than 5 microns.

27. The article of any one of claims 22-26, wherein the textured surface has a surface roughness of from about 20 nanometers to about 70 nanometers.

28. The article of claim 27, wherein the textured surface has a surface roughness of from about 30 nanometers to about 60 nanometers.

29. The article of claim 27 or claim 28, wherein the textured surface comprises concave, convex, honeycomb, bowl-shaped, or patterned features.

30. The article of claim 29, wherein the concave features are narrowly distributed and completely cover the textured surface.

31. The article of claim 29 or claim 30, wherein the concave features comprise a dimension of from about 4 microns to about 5 microns.

32. The article of claim 31, wherein the concave features comprise a dimension of from about 4.4 microns to about 4.8 microns.

33. The article of any one of claims 22 to 32, wherein the textured surface has a transmission haze of from about 2% to about 12%.

34. The article of any of claims 22 to 33, wherein the textured surface has a gloss at 60 degrees of from about 70GU to about 130 GU.

35. The article of any of claims 22 to 34, wherein the textured surface has a gloss at 60 degrees of from about 80GU to about 120 GU.

36. The article of any one of claims 22 to 35, wherein the textured surface has a distinctness of image (DOI) of less than about 99.6.

37. The article of any one of claims 22 to 36, wherein the textured surface has a DOI of less than about 99.4.

38. The article of any one of claims 22 to 37, wherein the textured surface has a lateral dimension of about 200 microns.

39. The article of claim 38, wherein the textured surface has a lateral dimension of about 100 microns.

40. The article of any one of claims 22 to 39, wherein the textured surface has a depth of about 30 microns, the depth defined by the arithmetic mean deviation of the roughness data distribution.

41. The article of any one of claims 22 to 40, wherein the textured surface has a depth of about 2 microns, the depth defined by the arithmetic mean deviation of the roughness data distribution.

42. The article of any one of claims 22 to 41, wherein the continuous density of features on the textured surface is from about 10% to about 100%.